Gasoline containing hydrazones



' tions.

U it d see Pa 7 This invention relates to improvements'in motor fuels,particularly in gasoline fuels for" internal combustion engines. Moreparticularly,"it relates to improvements elfectcd 'in gasoline: motorfuels by the incorporation therein of minor proportions of hydraznes.'

Gasoline suitable for use as a motor fuel is a complex mixtureconsisting largely of a yarie'tyof hydrocarbons .and usually. includesone or more non-hydrocarbon'materials added thereto to improvefthestorage ing characteristics of the fuel.

Few modern .gasolines are. straightv run fuels and the mixtureusually'lcontains' a substantial fraction of hydrocarbons obtained.by.'cracking,*isomerization, 'alkylati'on,

and operatpolymerization, r ef orming, hydroforming or other opera- Manyof these processes are designed to produce hydrocarbons which whenblended with straight-run gasdeleterious'tostorage'containers andpumps,as Well as feed lines, pump and carburetor in the automotive vehi-.'cle. j In ,addition,"they may give; rise Tin' the engine to materialswhich at;normal temperatures-of operationform resinous deposits onpistons, ringsgacylinder walls and bearings which interfere with properoperation of the automotive engine. fNurnerous -inhibitors, arecommer---cially available for, stabilization of gasoline ,in' these respectsand to improve qstorage and operatingcharacteristics of thefuel'byavoiding the fojrmation 10f resinous products of these unstablehydrocarbons. Most ofg the inhibitors are compounds of relatively highmolecular weight compared with gasoline hydrocarbons and are likely toremain as residues on evaporation of the fuel.

Motor gasoline is also usually blended with appropriate portions of'abutane fraction, particularly for Winter use to provide suflicientvolatility for easy starting. Many automotive engines, however, are notmaintained in good operating condition and difiicult startingischaracteristic of such engines even though the refiner provides asuitable fuel for engines in average or better condition. Addedtricresyl phosphate is advertised (as "improving startingcharacteristics.

Tetraethyl lead is commonly added to improve the anti-knock value of thegasoline and usually a mixture of halogen compounds is simultaneouslyadded to insure the vaporization of the combustion products of thetetraethyl lead. in addition, other materials may be added .to gasolinefor various purposes including light lubricating oils for uppercylindrical lubrication and many other dopes for various purposes.

The use of unsubstituted hydrazine as an additive is highly impracticalas hydrazine is substantially insoluble in hydrocarbons. It cannot,therefore, be incorporated in the fuel, but must be injected at somesuitable posioline -willimprove the anti-knock ,value. While thesehydrocarbons have high anti knock blending value, they -arecharacteristically lessstable. than the saturated hydro- ;.ca-rbons er,straight run' gasoline, 'Ifhelprocessedhydrocarbons are notablysubject'tdoxidation and polymerization in storage with'theforfiiationbfgummylprod'ucts wherein R1, R2, R3

one hetero atom. i p a 7 Examples of some hydrazones encompassed by this2,942,957 f Patented June l96Q I 2 tion in the fuel line orair intake bya suitable device. Furthermore, the presence of minor amounts ofunsubstituted hydrazine drastically reduces the octane rating ofgasoline by 10 or more octane units. 6

'According to the present invention, the addition of minor prop'ortionsof hydrazones or mixtures thereof to gasoline surprisingly improves thestorage, starting and otheroperating characteristics of the fuel. Thehydrazones fall Within the scope of the generic formula:

and R are selected from the group consisting of'hydrogen, aliphatichydrocarbon, alicyclic hydrocarbon, aromatic hydrocarbon andheterocyclic substituents. 'They canvbe the same or difierent. In theabove formula, the total number of carbon atoms should preferably notexceed 12. Compounds of up to and including 36 carbon atoms, however,have shown desirable properties and are included in the invention. A

wide variety of these-hydrazones is knownto the art and their method ofpreparationis'old, viz. condensation of an aldehyde ..or ketone .withhydrazine, a suitably monosubstituted hydrazine, or a N,N-disubstitutedhydraiine. "It is alsopossible for these substituents to carry'variousinnocuous groups, for example, 'anhydroxyl group or'ian ether 1g'roup.'Preferably, R R R and R are selected from. the group consisting ofhydrogen, alkyl, cycloalkyl, aryl and heteroc yclics containinginvention are:'

. Acetone hydrazone Formaldehyde dimethylhydra zone Acetaldehydedimethylhydrazone Formaldehyde diethylhydrazone Acetaldehydecyclohexylhydrazone Propionaldehyde phenylhydrazone Methyl ethyl ketonedimethylhydrazone Benz-aldehyde dimethylhydrazone Benzaldehydediphenylhydrazonel0. Benzaldehyde cyclopentylhydrazone ll. Benzaldehydeztpyridylhydrazone .The hydrazonesor mixtures thereof can be dissolved'tothe extent of .Q.l to 2 percent by weight in gasoline to providesuitable compositions according to'thepresent invention. Somewhatsmaller or larger amounts of the hydrazones or mixtures thereof can alsobe used, but preferably the amount used is within the range of fromabout 0.5 to 1 percent by weight, based on the gasoline.

The presence of hydrazones in gasoline improves its stability towardsthe action of oxygen in storage. The

hydrazones are reactive with dissolved oxygen and prevent its action onthe relatively unstable hydrocarbons by reacting more readily with theoxygen dissolved from the air. This activity of the hydrazones may notremove the necessity for incorporation of minor amounts of the usualanti-oxidants but it tends to reduce the quantity required in order toprovide satisfactory stability in storage. This in turn reduces theproportion of nonvolatile components in the gasoline and effectsimprovements in the cleanliness of lines, pumps and carburetors in whichthe gasoline is used.

Many hydrazones are sufliciently strong bases to combine with organicacids and they combine with 'most inorganic acids. Sulfuric acid derivedfrom organic sulfur contained in the fuel or other sources, phosphoricacid or hydrohalogen acids derived from other additives combine with thehydra'zone's and are neutralized to form relatively less corrosivesalts. This materially reduces corrosion of storage tanks and parts ofthe automotive vehicle which may be subject to such corrosion. Thealkalinity of the hydrazones further efiects improvements in reducingengine wear due to the removal or conversion of corrosive acids torelatively less corrosive materials.

Beneficial results are noticeable when as little as 0.1

percent by weight or less of a hydrazone is added and quantities of 2percent by weight or more can be used if desired. Ordinarily, withinthis range, material improvements are effected economically by theaddition of from about 0.5 to 1 percent by weight of a suitablehydrazone to the gasoline.

The hydrazones can be blended with the gasoline in any convenient manneror at any stage. They can be added as purecompounds or-rnay be dilutedwith" one of the heavier blending stocks to be used.

Example I A solution of 1 percent by weight-of acetaldehydecyclohexylhydrazone in gasoline is an example of this invention. 7 j sExample 11 Another example of this invention is a solution of 1 percentby weight of acetone hydrazone in gasoline.

Example III A blend of .85 percent by weight of benzaldehyde- 2-pyridylhydrazone and 99.15 percent by weight of gasoline is a furtherexample or this invention.

Example 1V An additional example of this invention is a solution of 2percent by weight of benzaldehyde dimethylhydrazone and 98 percent byweight of gasoline.

Example V A sample of stock gasoline containing 1 percent by weight ofacetaldehyde dimethylhydrazone was tested for its oxygen bomb stabilityaccording to ASTM method D525-49. The break point was reached in 960minutes Without any acetaldehyde dimethylhydrazone present, this breakpoint was reachedin 6l5minutes. This indicates that the fuels resistanceto oxidation was considerably increased by the addition of acetaldehydedimethylhydrazone.

Example Vl Two samples of stock gasoline were tested, according to themethod of Example V, one with and one without the addition of 1 percentby weight of benzaldehyde dimethylhydrazone. The break point was reachedin 615 minutes without this additive. However, 960'minutes were requiredto reach the break point with the sample containing the benzaldehydedimethylhydrazone.

I claim:

1. Gasoline containing as. an additive from 0.1 to 2 percent by weightof at least one of the materials falling within the scope of the formulaacetaldehyde cycloh'exylhydrazone.

5. Gasoline containing from 0.1 to 2 weight percent ofbenzaldehyde-Z-pyridylhydrazone.

6. Gasoline containing from 0.1 to 2 weight percent of benzaldehydedimethylhydrazone.

7. Gasoline containing from 0.1 to 2 weight percent of acetaldehydedimethylhydrazone.

References Cited in the file of this patent UNITED STATES PATENTS Burk.Apr. 25, 1933 1,958,744 Cross May 15, 1934 I 2,027,394- McMullan Jan.14, 1936 2,055,810 Bartram Sept. 29, 1936 2,339,984 Eitelman Jan. 25,1944 Chenicek July 26, 1955 OTHER REFERENCES industrial and EngineeringChemistry, vol. 42, September 1950, Hydrazine in Organic Chemistry," byByrkit and Michalek, pp. 1862 to 1875.

The Chemistry of Hydrazine, by Audrieth and Ogg,

'Wiley andSons Inc., 1951, pp. 225, 226 and 227. Scientific American,vol. 189, No. 1, July 1953,.Hydrazine, by Lessing, pp. 30 to 33.'

Journal of Organic Chemistry, vol; 15, 1950, pp. 1125-

1. GASOLINE CONTAINING AS AN ADDITIVE FROM 0.1 TO 2 PERCENT BY WEIGHT OFAT LEAST ONE OF THE MATERIALS FALLING WITHIN THE SCOPE OF THE FORMULA